An unfolded tesseract. A tesseract is a 4-dimensional analogue of a cube, as a cube is a 3-dimensional analogue of a square and is a theoretical projection of a four dimensional cube onto three dimensional space, analogous to an image, drawing or shadow of a cube as a projection of a three dimensional cube onto a two dimensional space (plane, sheet of paper). The unfolded version is analogous to the sides of a cube that have been folded out onto a flat plane. This version was made famous by Salvador Dali's painting: Corpus Hypercubus. Computer generated image.